PMID- 22298954
OWN - NLM
STAT- MEDLINE
DCOM- 20120523
LR  - 20211021
IS  - 1449-2288 (Electronic)
IS  - 1449-2288 (Linking)
VI  - 8
IP  - 2
DP  - 2012
TI  - Measurement of hepatic protein fractional synthetic rate with stable isotope 
      labeling technique in thapsigargin stressed HepG2 cells.
PG  - 265-71
LID - 10.7150/ijbs.3660 [doi]
AB  - Severe burn-induced liver damage and dysfunction is associated with endoplasmic 
      reticulum (ER) stress. ER stress has been shown to regulate global protein 
      synthesis. In the current study, we induced ER stress in vitro and estimated the 
      effect of ER stress on hepatic protein synthesis. The aim was two-fold: (1) to 
      establish an in vitro model to isotopically measure hepatic protein synthesis and 
      (2) to evaluate protein fractional synthetic rate (FSR) in response to ER stress. 
      Human hepatocellular carcinoma cells (HepG2) were cultured in medium supplemented 
      with stable isotopes 1,2-(13)C(2)-glycine and L-[ring-(13)C(6)]phenylalanine. ER 
      stress was induced by exposing the cells to 100 nM of thapsigargin (TG). Cell 
      content was collected from day 0 to 14. Alterations in cytosolic calcium were 
      measured by calcium imaging and ER stress markers were confirmed by Western 
      blotting. The precursor and product enrichments were detected by GC-MS analysis 
      for FSR calculation. We found that the hepatic protein FSR were 0.97 +/- 0.02 and 
      0.99 +/- 0.05%/hr calculated from 1,2-(13)C(2)-glycine and 
      L-[ring-(13)C(6)]phenylalanine, respectively. TG depleted ER calcium stores and 
      induced ER stress by upregulating p-IRE-1 and Bip. FSR dramatically decreased to 
      0.68 +/- 0.03 and 0.60 +/- 0.06%/hr in the TG treatment group (p<0.05, vs. control). 
      TG-induced ER stress inhibited hepatic protein synthesis. The stable isotope 
      tracer incorporation technique is a useful method for studying the effects of ER 
      stress on hepatic protein synthesis.
FAU - Song, Juquan
AU  - Song J
AD  - Department of Surgery, University of Texas Health Science Center, San Antonio, 
      Texas 78299, USA. songj4@uthscsa.edu
FAU - Zhang, Xiao-jun
AU  - Zhang XJ
FAU - Boehning, Darren
AU  - Boehning D
FAU - Brooks, Natasha C
AU  - Brooks NC
FAU - Herndon, David N
AU  - Herndon DN
FAU - Jeschke, Marc G
AU  - Jeschke MG
LA  - eng
GR  - R01 GM087285/GM/NIGMS NIH HHS/United States
GR  - T32 GM008256/GM/NIGMS NIH HHS/United States
GR  - T32-GM08256/GM/NIGMS NIH HHS/United States
GR  - R01-GM087285-01A2/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20120120
PL  - Australia
TA  - Int J Biol Sci
JT  - International journal of biological sciences
JID - 101235568
RN  - 0 (Carbon Isotopes)
RN  - 0 (Enzyme Inhibitors)
RN  - 67526-95-8 (Thapsigargin)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Calcium/metabolism
MH  - Carbon Isotopes
MH  - Cytosol/metabolism
MH  - Endoplasmic Reticulum/drug effects
MH  - Enzyme Inhibitors/pharmacology
MH  - Gene Expression Regulation/*drug effects
MH  - Hep G2 Cells
MH  - Hepatocytes/*drug effects/*metabolism
MH  - Humans
MH  - Models, Biological
MH  - Protein Biosynthesis/*drug effects
MH  - Stress, Physiological
MH  - Thapsigargin/*pharmacology
PMC - PMC3269609
OTO - NOTNLM
OT  - Endoplasmic reticulum (ER) stress
OT  - Gas chromatography-mass spectrometry (GC-MS)
OT  - Hepatic protein synthesis
OT  - calcium
OT  - in vitro
COIS- Conflict of Interests: The authors have declared that no conflict of interest 
      exists.
EDAT- 2012/02/03 06:00
MHDA- 2012/05/24 06:00
PMCR- 2012/01/01
CRDT- 2012/02/03 06:00
PHST- 2011/10/18 00:00 [received]
PHST- 2012/01/10 00:00 [accepted]
PHST- 2012/02/03 06:00 [entrez]
PHST- 2012/02/03 06:00 [pubmed]
PHST- 2012/05/24 06:00 [medline]
PHST- 2012/01/01 00:00 [pmc-release]
AID - ijbsv08p0265 [pii]
AID - 10.7150/ijbs.3660 [doi]
PST - ppublish
SO  - Int J Biol Sci. 2012;8(2):265-71. doi: 10.7150/ijbs.3660. Epub 2012 Jan 20.